Likely causes:
Plain and simple, this is an overuse injury. The pain is your adductor muscle calling attention to itself, complaining that it's been held too tense. The adductor is the muscle that runs along the inner thigh and is involved in turning in your toes, a natural motion when running. It's possible that you got this injury when running on a slippery surface; it's a natural instinct to tense your adductors to keep balance, but it can result in a groin pull.

For others, though, it could be a foot imbalance. If there's not enough range of motion in your ankle, the adductor tends to tighten to help you keep your balance.

Remedy:
This injury takes patience and more than a little dedication to overcome. It's not what you want to hear, but you'll have to stop running -- or at least cut back drastically -- for about a week. After the pain has gone away, and not before, gently stretch the area with the groin stretch, and try the inside leg raise for a strengthening exercise. Do these stretches, they'll get you back on the road. After seven days of stretching, try a little easy running, starting with just a mile. Keep doing the exercises, and gradually build your mileage. If the pain keeps up, take a few more days off.

At the same time, try putting a wedge in your shoes, at the inner side of the heel. If you don't have enough range of motion in your ankles, as mentioned above, a wedge will help your ankles and heels turn out with less strain on your adductors. Try cutting a wedge out of foam rubber (like a makeup sponge), about 1/2" thick at the widest part.

If the pain persists after these treatments, consult a podiatrist on whether orthotics may be needed.

Description:
Pain in the back of the thigh. You probably have trouble running at your usual pace and find that it's much more comfortable to take short quick strides than your usual longer ones. Be aware that many runners confuse a hamstring pull with sciatica, which occurs when a nerve running from your back down your legs is pinched. It's important to know what you have, since treatment for a hamstring pull can sometimes aggravate sciatica. If the pain is centered in the back of the thigh, it's probably a hamstring pull, while sciatica is usually painful at the outer side of the thigh and often in the hip and lower back, sometimes all the way down to your feet.

With a hamstring pull, you have difficulty extending your leg without pain. Try this test: lie on your back and try to raise one leg, knee straight (if it's a hamstring pull, you probably won't be able to get this far). Have someone flex your foot, bending your toe toward your knee. If you have sciatica, this will be very painful, something akin to a burning electric shock down your leg or in the small of your back. Finally, feel the back of your thigh and look for a lump. If you find one, possibly accompanied by a bruise, it's a hamstring pull.

Likely causes:
Your hamstring is the muscle that goes from your buttock to the back of your knee. You've injured it either by overextending it or by extending it too quickly too many times. Sprinting or running downhill, especially at speeds you are not accustomed to, are likely causes. Also, consider whether you have been running on a banked surface. On roads that slope at the sides, for example, you effectively have one long leg and one short leg. The short leg has to extend further in order to keep up with the longer one, and you may overdo it, tearing your hamstring.

Remedy:
For immediate relief, ice your hamstring right after running. You may either use a commercially available cold pack or simply put a wet towel in the freezer before you go out for your run. Wrap the pack around your leg for fifteen minutes. Also, take an anti-inflammatory like ibuprofen or aspirin with meals, but never before running, to bring down the swelling.

The good news is that you can keep running. In fact, it's part of your treatment to help gradually stretch and extend your hamstring. Just take it easy, using short steps that don't require you to extend your legs too much. If you've been running on a banked track or road and you have a hamstring pull in your "short leg," try reversing directions so that your other leg has the chance to be the short leg. Better yet, try to find a flat surface to run on.

Finally, when doing your stretching, pay particular attention to the hamstring stretch. Be gentle, though, and don't force the muscle to stretch farther than it is willing; there should never be any discomfort when you stretch.

If you have a simple cramp in your hamstring, this treatment should take care of it in about three days. If it's a pull, the pain should be much relieved after seven to ten days of this regimen. If the pain eases only a little or not at all, go to see an osteopath.

Description:
Pain in the front of the thigh. A severe tear (sudden pain without warning), may be accompanied by swelling or bruises.

Likely causes:
This injury is almost certainly due to a strength imbalance between your quadricep and your hamstring (the muscle at the back of your thigh). Basically, your hamstring overpowered your quadricep and caused it to tear. This muscle imbalance is not uncommon among runners, since running tends to work out the hamstrings much more than the quadriceps.

Remedy:
For immediate relief, ice the muscle right after running. You may either use a commercially available cold pack or simply put a wet towel in the freezer before you go out for your run. Wrap the pack around your leg for fifteen minutes. Also, take an anti-inflammatory like ibuprofen or aspirin with meals, but never before running, to bring down the swelling. After applying the ice, wrap your thigh in an ACE bandage to keep it compressed.

You can continue running, but take it easy, and pay careful attention to stretching your quadriceps. Do it gently, but thoroughly. See exercises six and, in particular, seven on our stretching page. Don't force the stretch; there should never be any discomfort when you're stretching. With gentle running and stretching, you can probably be back to normal in two or three weeks.

The way to prevent this injury in the future is to strengthen your quadriceps. As your legs continue to improve, you might consider doing some biking and leg lifts to help strengthen your quadriceps.